Few-layer phosphorene (FL-P) isolated by micromechanical exfoliation has been widely studied, both fundamentally and in applications such as high-performance electronic and optoelectronic devices. Although micromechanical exfoliation provides individual, high-quality FL-P flakes, this technique is not scalable and is not amenable to large-area applications. Conventional approaches for mass production of two-dimensional (2D) nanomaterials involve chemical vapor deposition (CVD) and liquid phase exfoliation (LPE). Whereas CVD growth of black phosphorus (BP) thin films is hindered by challenges with molecular precursors and extreme growth conditions, LPE of BP has been demonstrated and used for the large-scale deposition of thin films, following approaches for other 2D nanomaterials. Specifically, stable BP dispersions have been produced by LPE using high boiling point solvents such as N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and N-cyclohexyl-2-pyrrolidone (CHP). With these anhydrous organic solvents, chemical degradation from ambient O2 and water are avoided, but the exfoliation yield and flake size distribution are suboptimal. Furthermore, organic solvents have limited compatibility with methods such as ultracentrifugation, preventing structural fine tuning and sorting. Such solvents also have high boiling points and safety issues, presenting post-processing challenges.